* {
  margin: 0;
  padding: 0;
}
.warper {
  width: 800px;
  height: 45px;
  margin: 300px auto;
}
.warper .left {
  width: 740px;
  height: 45px;
  background-color: #ccc;
  border-radius: 10px;
  float: left;
  position: relative;
}
.warper .left .cover {
  width: 0px;
  height: 45px;
  background-color: lawngreen;
  border-top-left-radius: 10px;
  border-bottom-left-radius: 10px;
}
.warper .left .remove {
  width: 10px;
  height: 50px;
  background-color: skyblue;
  border-radius: 10px;
  top: -3px;
  left: 0px;
  cursor: move;
  position: absolute;
}
.warper .number {
  line-height: 55px;
  float: left;
  margin-left: 650px;
  text-align: center;
  width: 100px;
  font-weight: 700;
  color: blue;
}
